Population dynamics and health status of free-roaming dogs in Bhutan

Rinzin, K. 2015. Population dynamics and health status of free-roaming dogs in Bhutan. Thesis disertation. Murdoch UniversityWestern Australia 

In 2009 a capture-neuter-vaccinate-release (CNVR) programme commenced in Bhutan to control the dog population and to reduce the number of cases of rabies in humans and other animals. Limited understanding of the community’s attitudes towards dog population control and the population dynamics of the free-roaming dog population in Bhutan motivated the study reported in this thesis.
Household surveys were undertaken in six Dzongkhags to determine the knowledge, attitudes and practices of the community towards dog population control and to describe the demographics and management of owned dogs. Approximately 90% of the Bhutanese community believed that stray dogs were a problem to society and 77% believed they presented a threat to human health. Most participants (84%) were in favour of dog population control with birth control being the preferred method. A need to develop educational programmes on rabies and the dog population specifically
targeting farmers and women from rural areas was identified. The total owned dog population was estimated at 71,245 with 24.4% of the households in the urban areas and 0.8% of the households in rural areas owning dogs. Forty percent of dog owners did not confine their dogs. Based on the number of owned dogs and the ratio of owned to stray dogs presented to the CNVR clinic, the stray dog population was estimated at 48,379.
The population characteristics of both owned and stray dogs that were presented to CNVR clinics from 01 July 2011 to 30 June 2013 were described. More than half (53.3%) of the dogs presented to the CNVR clinic were free-roaming dogs, with comparable numbers of males and females presented. Although pregnant bitches were seen throughout the year, more pregnancies were observed from September to December.
Field population survey undertaken in the main towns of six Dzongkhags to estimate the programme’s coverage in January and February 2012 showed overall CNVR coverage of 52% ranging from 32% in Bumthang to 72% in Samdrup Jongkhar. Field population survey was undertaken in Thimphu city to estimate the size of the free-roaming dog population and to assess the health status of dogs. The free-roaming dog population in Thimphu Municipal area was highest in June 2011 at 6,033 (95% CI 5,644 – 6,430), prior to which there had been no CNVR campaign for 15 months. From July 2011 to September 2014 the free-roaming dog population size remained relatively constant (range 5,765 to 5,949 dogs) as CNVR campaigns were regularly carried out. Neutered dogs had a significantly lower prevalence of antibodies to canine distemper virus (44.2%) and canine parvovirus CPV (4.0%) than entire dogs (52.9 & 18.4%, respectively) (P < 0.01); and neutered dogs had significantly higher body condition scores than entire dogs (P < 0.01).
The studies presented in this thesis have demonstrated that the success of a CNVR programme will depend on the initial planning of the programme which includes assessing the size of the local dog population and continuous monitoring and evaluation of the programme. To effectively control the dog population in Bhutan and to address problems associated with free-roaming dogs, it is recommended that: regular CNVR programmes are carried out throughout the country; female dogs, especially during the breeding season, are specifically targeted; programmes are monitored regularly;
community participation in programmes is encouraged; and legislation on responsible dog ownership is implemented.

Methods to estimate abundance and rabies vaccination coverage in Bhutan

Tenzin, T., McKenzie, J. S., Vanderstichel, R., Rai, B. D., Rinzin, K., Tshering, Y., Pemd, R., Tsheringf, C., Dahala, N., Dukpaa, K., Dorjeed, S., Wangchukh, S., Jollyb, P.D., Morrisi, R. & Ward, M. P. (2015). Comparison of mark-resight methods to estimate abundance and rabies vaccination coverage of free-roaming dogs in two urban areas of south Bhutan. Preventive Veterinary Medicine. Preventive Veterinary Medicine

In Bhutan, Capture-Neuter-Vaccinate-Release (CNVR) programs have been implemented to manage the dog population and control rabies, but no detailed evaluation has been done to assess their coverage and impact. We compared estimates of the dog population using three analytical methods: Lincoln-Petersen index, the Chapman estimate, and the logit-normal mixed effects model, and a varying number of count periods at different times of the day to recommend a protocol for applying the mark-resight framework to estimate free-roaming dog population abundance. We assessed the coverage of the CNVR program by estimating the proportion of dogs that were ear-notched and visually scored the health and skin condition of free-roaming dogs in Gelephu and Phuentsholing towns in south Bhutan, bordering India, in September–October 2012.

The estimated free-roaming dog population in Gelephu using the Lincoln-Petersen index and Chapman estimates ranged from 612 to 672 and 614 to 671, respectively, while the logit-normal mixed effects model estimate based on the combined two count events was 641 (95% CI: 603-682). In Phuentsholing the Lincoln-Petersen index and Chapman estimates ranged from 525 to 583 and 524 to 582, respectively, while the logit-normal mixed effects model estimate based on the combined four count events was 555 (95% CI: 526-587). The total number of dogs counted was significantly associated with the time of day (AM versus PM; P = 0.007), with a 17% improvement in dog sightings during the morning counting events. We recommend to conduct a morning marking followed by one count event the next morning and estimate population size by applying the Lincoln-Peterson corrected Chapman method or conduct two morning count events and apply the logit-normal mixed model to estimate population size.

The estimated proportion of vaccinated free-roaming dogs was 56% (95% CI: 52–61%) and 58% (95% CI: 53–62%) in Gelephu and Phuentsholing, respectively. Given coverage in many neighbourhoods was below the recommended threshold of 70%, we recommend conducting an annual “mass dog vaccination only” campaign in southern Bhutan to create an immune buffer in this high rabies-risk area. The male-to-female dog ratio was 1.34:1 in Gelephu and 1.27:1 in Pheuntsholing.

Population size estimates using mark-resight surveys has provided useful baseline data for understanding the population dynamics of dogs at the study sites. Mark–resight surveys provide useful information for designing and managing the logistics of dog vaccination or CNVR programs, assessing vaccination coverage, and for evaluating the impact of neutering programs on the size and structure of dog populations over time.

Participatory approach to control free roaming dogs

Schurer, J. M., Phipps, K., Okemow, C., Beatch, H., & Jenkins, E. (2014). Stabilizing Dog Populations and Improving Animal and Public Health Through a Participatory Approach in Indigenous Communities. Zoonoses and Public Health.

Free-roaming dog populations are a global concern for animal and human health including transmission of infectious disease (e.g. rabies, distemper and parasites), dog bite injuries/mortalities, animal welfare and adverse effects on wildlife. In Saskatchewan (SK), Canada, veterinary care is difficult to access in the remote and sparsely inhabited northern half of the province, where the population is predominately Indigenous. Even where veterinary clinics are readily available, there are important barriers such as cost, lack of transportation, unique cultural perspectives on dog husbandry and perceived need for veterinary care. We report the effects of introducing a community action plan designed to improve animal and human health, increase animal health literacy and benefit community well-being in two Indigenous communities where a dog-related child fatality recently occurred. Initial door-to-door dog demographic surveys indicated that most dogs were sexually intact (92% of 382 dogs), and few had ever been vaccinated (6%) or dewormed (6%). Approximately three animal-related injuries requiring medical care were reported in the communities per 1000 persons per year (95% CL: 1.6–6.6), and approximately 83% of 101 environmentally collected dog faecal samples contained parasites, far above levels reported in other urban or rural settings in SK. Following two subsidized spay/neuter clinics and active rehoming of dogs, parasite levels in dog faeces decreased significantly (P < 0.001), and important changes were observed in the dog demographic profile. This project demonstrates the importance of engaging people using familiar, local resources and taking a community specific approach. As well, it highlights the value of integrated, cross-jurisdictional cooperation, utilizing the resources of university researchers, veterinary personnel, public health, environmental health and community-based advocates to work together to solve complex issues in One Health. On-going surveillance on dog bites, parasite levels and dog demographics are needed to measure the long-term sustainability of benefits to dog, human and wildlife health.

Dog ecology and demography in Machakos District, Kenya

Kitala, P., McDermott, J., Kyule, M., Gathuma, J., Perry, B., & Wandeler, A. (2001). Dog ecology and demography information to support the planning of rabies control in Machakos District, Kenya. Acta Tropica, 78(3), 217-230.

A study of 150 dog-owning households from six randomly selected sublocations was conducted in Machakos District, Kenya. Initially, all households were visited to collect information on dog ecology and demography based on WHO guidelines and to collect serum for rabies antibody detection. A second visit was made 1 year later, to obtain follow-up data on births, deaths, dog movements and other events since the first visit. Dog ownership was common, with a range of 53–81% (mean=63%) of households owning dogs in the six sublocations. Dog density for the five more rural sublocations ranged from 6 to 21 dogs  km^-2 and for the peri-urban sublocation was 110 dogs  km^-2. The dog population was estimated to be growing at 9% p.a. (95% C.I. 4–14%). This growth was a function of very high fecundity (1.3 females per female per year) more than compensating for high mortality, particularly among females. Life expectancy from birth was 3.5 years for males and 2.4 years for females. Half the dogs at any one time were less than 1 year of age. All dogs, by design of the study, were owned. Of these, 69% were never restricted and roamed freely to forage for food and mix with other dogs. Only a small proportion of dogs (5%) were fed commercial dog food. Most households reported observing dogs scavenging their garbage, including: their own dogs (81%), their neighbours’ dogs (75%) and unknown dogs (45%). Only 29% of dogs at least 3 months of age were reported to be vaccinated against rabies. The proportion vaccinated varied widely between sublocations (5–68%); 48% of dogs reportedly vaccinated had detectable antibodies, 31% at or above levels considered to indicate seroconversion. The proportion of dogs with detectable antibodies declined according to the time since last vaccination (55% if vaccinated ≤1 year, 47% ≤2 years and 36% >2 years); 20% of dogs reported not to have been vaccinated had detectable rabies antibody. Compared to other dog populations in rural eastern and southern Africa, Machakos District has a high density of dogs. The Machakos dog population is growing, highly dynamic, poorly supervised and inadequately vaccinated against rabies. The main implication for rabies control is that adequate vaccination coverage is unlikely to be achieved, even under optimal delivery, using the current strategy of annual vaccination of dogs older than 3 months.

Dog ecology and demography in Antananarivo

Ratsitorahina, M., Rasambainarivo, J. H., Raharimanana, S., Rakotonandrasana, H., Andriamiarisoa, M. P., Rakalomanana, F. A., & Richard, V. (2009). Dog ecology and demography in Antananarivo, 2007. BMC veterinary research, 5(1), 21.

Background

Rabies is a widespread disease in African domestic dogs and a serious public health problem in developing countries. Canine rabies became established in Africa during the 20th century, coinciding with ecologic changes that favored its emergence in canids.

This paper reports the results of a cross-sectional study of dog ecology in the Antananarivo urban community in Madagascar.

A questionnaire survey of 1541 households was conducted in Antananarivo from October 2007 to January 2008. The study addressed both owned and unowned dogs. Various aspects of dog ecology were determined, including size of dog population, relationship between dogs and humans, rabies vaccination.

Results

Dog ownership was common, with 79.6 to 94.1% (mean 88.9%) of households in the six arrondissements owning dogs. The mean owned dog to person ratio was 1 dog per 4.5 persons and differed between arrondissements (administrative districts), with ratios of 1:6.0 in the first arrondissement, 1:3.2 persons in the 2nd, 1:4.8 in the 3rd, 1:5.2 in the 4th, 1:5.6 in the 5th and 1:4.4 in the 6th arrondissement. Overall, there were more male dogs (61.3%) and the male/female sex ratio was estimated to be 1.52; however, mature females were more likely than males to be unowned (OR: 1.93, CI 95%; 1.39<OR<2.69). Most (79.1%) owned dogs were never restricted and roamed freely to forage for food and mix with other dogs. Only a small proportion of dogs (11.7%) were fed with commercial dog food. Only 7.2% of owned dogs had certificates confirming vaccination against rabies. The proportion of vaccinated dogs varied widely between arrondissements (3.3% to 17.5%).

Conclusion

Antananarivo has a higher density of dogs than many other urban areas in Africa. The dog population is unrestricted and inadequately vaccinated against rabies. This analysis of the dog population will enable targeted planning of rabies control efforts.

Bait preference testing for rabies oral vaccination

Berentsen, A. R., Bender, S., Bender, P., Bergman, D., Hausig, K., & VerCauteren, K. C. (2014). Preference among seven bait flavors delivered to domestic dogs in Arizona: implications for oral rabies vaccination on the Navajo Nation. Journal of Veterinary Behavior: Clinical Applications and Research.

Less than 20% of domestic dogs on tribal lands in the United States are vaccinated against rabies. One method to increase vaccination rates may be the distribution of oral rabies vaccines (ORV). ONRAB^® is the primary ORV bait used in Canada to vaccinate striped skunks and raccoons. To investigate the potential use of ONRAB^® ORV baits to vaccinate feral domestic dogs against rabies on tribal lands and beyond, we performed a flavor preference study. Seven bait flavors (bacon, cheese, dog food, hazelnut, sugar-vanilla, peanut butter and sardine) were offered in pairs to 13 domestic dogs. Each dog was offered all possible combinations of bait pairs over a period of ten days, with each bait offered six times. The proportion of times each bait was consumed first by individual dogs was calculated and comparisons among dogs were conducted using the MIXED procedure in SAS. Pairwise comparisons between baits were performed using “contrast” statements with sugar-vanilla flavor as the default for comparison. Type three tests of fixed effects showed a significant treatment effect (F_6,72 = 9.74, P < 0.0001). Sugar-vanilla was selected first during 14% of offerings and exhibited the least preference among all bait types (F_1,72 = 22.46, P < 0.0001). Dog food was selected first 56% of the time, and more frequently than all other bait types (F_1,72 = 13.09, P = 0.0005).